scholarly journals Comparative activity of Ceftriaxone, Ciprofloxacin and Gentamicin as a function of bacterial growth rate probed by Escherichia coli chromosome replication in the mouse peritonitis model

2018 ◽  
Author(s):  
Maria Schei Haugan ◽  
Anders Løbner-Olesen ◽  
Niels Frimodt-Møller
Keyword(s):  
Growth Rate ◽  
Bacterial Growth ◽  
Growth Dynamics ◽  
Chromosome Replication ◽  
Bacterial Cells ◽  
Bacterial Growth Rate ◽  
Pre Treatment

AbstractCommonly used antibiotics exert their effect predominantly on rapidly growing bacterial cells, yet growth dynamics taking place during infection in a complex host environment remain largely unknown. Hence, means to measure in situ bacterial growth rate is essential to predict the outcome of antibacterial treatment. We have recently validated chromosome replication as readout for in situ bacterial growth rate during Escherichia coli infection in the mouse peritonitis model. By the use of two complementary methods (qPCR and fluorescence microscopy) for differential genome origin and terminus copy number quantification, we demonstrated the ability to track bacterial growth rate, both on a population average and on a single-cell level; from one single biological specimen. Here, we asked whether the in situ growth rate could predict antibiotic treatment effect during infection in the same model. Parallel in vitro growth experiments were conducted as proof-of-concept. Our data demonstrate that the activity of commonly used antibiotics Ceftriaxone and Gentamicin correlated with pre-treatment bacterial growth rate; both drugs performing better during rapid growth than during slow growth. Conversely, Ciprofloxacin was less sensitive to bacterial growth rate, both in a homogenous in vitro bacterial population and in a more heterogeneous in vivo bacterial population. The method serves as a platform to test any antibiotic’s dependency upon active in situ bacterial growth. Improved insight into this relationship in vivo could ultimately prove helpful in evaluating future antibacterial strategies.ImportanceMost antibiotics in clinical use exert their effect predominantly on rapidly growing bacterial cells, yet there is a lack of insight into bacterial growth dynamics taking place during infection in vivo. We have applied inexpensive and easily accessible methods for extraction of in situ bacterial growth rate from bacterial chromosome replication during experimental murine infection. This approach not only allows for a better understanding of bacterial growth dynamics taking place during the course of infection, but also serves as a platform to test the activity of different antibiotics as a function of pre-treatment in situ growth rate. The method has the advantage that bacterial growth rate can be probed from a single biological sample, with the potential for extension into clinical use in pre-treatment infected biological specimens. A better understanding of commonly used antibiotics’ level of dependency upon bacterial growth, combined with measurements of in situ bacterial growth rate in infected clinical specimens, could prove helpful in evaluating future antibacterial treatment regimens.

scholarly journals Comparative Activity of Ceftriaxone, Ciprofloxacin, and Gentamicin as a Function of Bacterial Growth Rate Probed by Escherichia coli Chromosome Replication in the Mouse Peritonitis Model

2018 ◽  
Vol 63 (2) ◽  
pp. e02133-18 ◽  
Author(s):  
Maria Schei Haugan ◽  
Anders Løbner-Olesen ◽  
Niels Frimodt-Møller
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Bacterial Population ◽  
Chromosome Replication ◽  
Bacterial Growth Rate ◽  
Peritonitis Model

ABSTRACT Commonly used antibiotics exert their effects predominantly on rapidly growing bacterial cells; yet, the growth dynamics taking place during infection in a complex host environment remain largely unknown. Hence, a means to measure in situ bacterial growth rate is essential to predict the outcome of antibacterial treatment. We have recently validated chromosome replication as a readout of in situ bacterial growth rate during Escherichia coli infection in the mouse peritonitis model. By the use of two complementary methods (quantitative PCR and fluorescence microscopy) for differential genome origin and terminus copy number quantification, we demonstrated the ability to track bacterial growth rate, both on a population average level and on a single-cell level, from one single biological specimen. Here, we asked whether the in situ growth rate predicts antibiotic treatment effect during infection in the same model. Parallel in vitro growth experiments were conducted as a proof of concept. Our data demonstrate that the activities of the commonly used antibiotics ceftriaxone and gentamicin correlated with pretreatment bacterial growth rate; both drugs performed better during rapid growth than during slow growth. Conversely, ciprofloxacin was less sensitive to bacterial growth rate, both in a homogenous in vitro bacterial population and in a more heterogeneous in vivo bacterial population. The method serves as a platform to test any antibiotic’s dependency on active in situ bacterial growth. Improved insight into this relationship in vivo could ultimately prove helpful in evaluating future antibacterial strategies.

Effect of Tannins on the In Vitro Growth of Escherichia coli O157:H7 and In Vivo Growth of Generic Escherichia coli Excreted from Steers

2007 ◽  
Vol 70 (3) ◽  
pp. 543-550 ◽  
Author(s):  
BYENG R. MIN ◽  
WILLIAM E. PINCHAK ◽  
ROBIN C. ANDERSON ◽  
TODD R. CALLAWAY
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Escherichia Coli O157 ◽  
Tannin Extract ◽  
Bacterial Growth Rate ◽  
Linear Effect ◽  
E Coli

The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement of optical density at 600 nm during anaerobic culture in tryptic soy broth at 37°C, was reduced (P < 0.05) with as little as 400 μg of either tannin extract per ml of culture fluid. The addition of 200, 400, 600, 800, and 1,200 μg of tannins per ml significantly (P < 0.01) reduced the specific bacterial growth rate when compared with the nontannin control. The specific growth rate decreased with increasing dose levels up to 800 μg of tannins per ml. Bacterial growth inhibition effects in chestnut tannins were less pronounced than in mimosa tannins. Chestnut tannin extract addition ranged from 0 to 1,200 μg/ml, and a linear effect (P < 0.05) was observed in cultures incubated for 6 h against the recovery of viable cells, determined via the plating of each strain onto MacConkey agar, of E. coli O157:H7 strains 933 and 86-24, but not against strain 6058. Similar tests with mimosa tannin extract showed a linear effect (P < 0.05) against the recovery of E. coli O157:H7 strain 933 only. The bactericidal effect observed in cultures incubated for 24 h with the tannin preparations was similar, although it was less than that observed from cultures incubated for 6 h. When chestnut tannins (15 g of tannins per day) were infused intraruminally to steers fed a Bermuda grass hay diet in experiment 2, fecal E. coli shedding was lower on days 3 (P < 0.03), 12 (P = 0.08), and 15 (P < 0.001) when compared with animals that were fed a similar diet without tannin supplementation. It was concluded that dietary levels and sources of tannins potentially reduce the shedding of E. coli from the gastrointestinal tract.

scholarly journals Growth Rate of Escherichia coli During Human Urinary Tract Infection: Implications for Antibiotic Effect

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 92 ◽  
Author(s):  
Haugan ◽  
Hertz ◽  
Charbon ◽  
Sahin ◽  
Løbner-Olesen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Bacterial Growth ◽  
Chromosome Replication ◽  
Bacterial Growth Rate ◽  
E Coli ◽  
Antibiotic Effect

Escherichia coli is the primary cause of urinary tract infection (UTI), which is one of the most frequent human infections. While much is understood about the virulence factors utilized by uropathogenic E. coli (UPEC), less is known about the bacterial growth dynamics taking place during infection. Bacterial growth is considered essential for successful host colonization and infection, and most antibiotics in clinical use depend on active bacterial growth to exert their effect. However, a means to measure the in situ bacterial growth rate during infection has been lacking. Due to faithful coordination between chromosome replication and cell growth and division in E. coli, chromosome replication provides a quantitative measure of the bacterial growth rate. In this study, we explored the potential for inferring in situ bacterial growth rate from a single urine sample in patients with E. coli bacteriuria by differential genome quantification (ori:ter) performed by quantitative PCR. We found active bacterial growth in almost all samples. However, this occurs with day-to-day and inter-patient variability. Our observations indicate that chromosome replication provides not only a robust measure of bacterial growth rate, but it can also be used as a means to evaluate antibiotic effect.

scholarly journals Revealing the in vivo growth and division patterns of mouse gut bacteria

2020 ◽  
Vol 6 (36) ◽  
pp. eabb2531
Author(s):  
Liyuan Lin ◽  
Qiuyue Wu ◽  
Jia Song ◽  
Yahui Du ◽  
Juan Gao ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gut Microbiota ◽  
Growth Dynamics ◽  
Gut Bacteria ◽  
Metabolic Labeling ◽  
Taxonomic Identification ◽  
In Vivo Growth

Current techniques for studying gut microbiota are unable to answer some important microbiology questions, like how different bacteria grow and divide in the gut. We propose a method that integrates the use of sequential d-amino acid–based in vivo metabolic labeling with fluorescence in situ hybridization (FISH), for characterizing the growth and division patterns of gut bacteria. After sequentially administering two d-amino acid–based probes containing different fluorophores to mice by gavage, the resulting dual-labeled peptidoglycans provide temporal information on cell wall synthesis of gut bacteria. Following taxonomic identification with FISH probes, the growth and division patterns of the corresponding bacterial taxa, including species that cannot be cultured separately in vitro, are revealed. Our method offers a facile yet powerful tool for investigating the in vivo growth dynamics of the bacterial gut microbiota, which will advance our understanding of bacterial cytology and facilitate elucidation of the basic microbiology of this gut “dark matter.”

Effect of hormone pre-treatment of prepubertal sheep on the production and developmental capacity of oocytes in vitro and in vivo

1997 ◽  
Vol 9 (6) ◽  
pp. 625 ◽  
Author(s):  
J. K. O'Brien ◽  
N. F. G. Beck ◽  
W. M. C. Maxwell ◽  
G. Evans
Keyword(s):  
In Vitro Maturation ◽  
Single Treatment ◽  
Oocyte Collection ◽  
Oestradiol Benzoate ◽  
Developmental Capacity ◽  
Pre Treatment ◽  
Pregnant Mare Serum Gonadotrophin

Twenty 36-week-old Merino lambs were given either 3, 1 or 0 treatments of 50 µg oestradiol benzoate and (48 h later) a 1·5 mg Norgestamet implant left in situ for 9 days (3-, 1- and 0CYCLE+G). On Day 7 after the last implant insertion, and on the same day for 0CYCLE+G, each lamb received 400 I.U. pregnant mare serum gonadotrophin and 6 mg follicle-stimulating hormone (FSH). The reproductive tracts were removed for oocyte collection 24 h after FSH. Reproductive tracts were also collected from 16-24-week-old lambs (n = 31) (0CYCLEG). The number of antral follicles per ovary was similar for the 3-, 1- and 0CYCLE+G treatments. Similar rates of in vitro maturation and monospermic fertilization were obtained for all groups. The proportion of blastocysts per cleaved oocyte was higher for 1CYCLE+G (50·5%) than for 3CYCLE+G (32·9%), 0CYCLE+G (24·3%), and 0CYCLEG (11·8%) (P < 0·05). Viable fetuses were obtained at Day 93 of pregnancy after transfer of embryos from all treatments. These results indicate that a single treatment with oestrogen and progesterone, prior to gonadotrophin stimulation, will increase the yield and developmental capacity of oocytes from prepubertal sheep.

scholarly journals Effect of Turmeric Concentrations on the Rate of Growth of Oral Bacteria—An In-Vitro Study

2021 ◽  
Vol 9 (3) ◽  
pp. 26
Author(s):  
Yun Xuan Yang ◽  
Vicky Wu ◽  
Hadi Malak ◽  
Aliya Peer Ahamed ◽  
Aaron Lo ◽  
...  
Keyword(s):  
Growth Rate ◽  
Bacterial Growth ◽  
Growth Rates ◽  
Dental Students ◽  
Oral Bacteria ◽  
Growth Data ◽  
Bacterial Growth Rate ◽  
Bacterial Cultures ◽  
Significant Difference

Background and Aim: The aim of this study was to evaluate the effect of varying concentrations of a turmeric solution on the growth rates of oral bacteria sampled from dental students. Methods: Bacterial cultures were grown overnight in aerobic conditions from plaque samples obtained from five test subjects. With the exception of the control, samples were exposed to different treatments; including chlorhexidine gluconate 2 mg/mL, prepared turmeric solution (TS) mouthwash: TS 0.25 mL (7.375 mg/mL), TS 0.5 mL (14.75 mg/mL), and TS 1 mL (29.50 mg/mL). Growth rate of the bacterial cultures were assessed by monitoring changes in optical density readings at 600 nm at hourly intervals for a six-hour period. The data were plotted and the exponential trend was used to calculate individual rates of growth. Data was analyzed using a one-way ANOVA with the significance confirmed using the Tukey-HSD test. Results: Growth observed in the bacteria exposed to the turmeric solution, was significantly greater (p < 0.05) when compared with the bacteria exposed to the medium alone. There was a significant difference found between the bacterial growth rate of the 1 mL turmeric solution against the growth rate of the bacteria in the 0.25 and 0.5 mL turmeric solutions. Conclusion: Comparison of growth rates of oral bacteria suggested that turmeric solutions of concentrations between 7.357 and 29.5 mg/mL (0.25–1 mL) were unlikely to exhibit bacteriostatic or bactericidal properties, and, conversely, increased bacterial growth. Considering this result, it is unlikely that turmeric mouthwash made from store-bought turmeric would have any antibacterial effects against oral bacteria, and may even promote bacterial growth.

scholarly journals The highly conserved chromosomal periodicity of transcriptomes and the correlation of its amplitude with the growth rate in Escherichia coli

DNA Research ◽  
2020 ◽  
Vol 27 (3) ◽  
Author(s):  
Motoki Nagai ◽  
Masaomi Kurokawa ◽  
Bei-Wen Ying
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Bacterial Population ◽  
Growth Dynamics ◽  
Culture Conditions ◽  
Bacterial Growth Rate ◽  
Global Pattern ◽  
Microbial Genomes ◽  
Chromosomal Distance

Abstract The growth rate, representing the fitness of a bacterial population, is determined by the transcriptome. Chromosomal periodicity, which is known as the periodic spatial pattern of a preferred chromosomal distance in microbial genomes, is a representative overall feature of the transcriptome; however, whether and how it is associated with the bacterial growth rate are unknown. To address these questions, we analysed a total of 213 transcriptomes of multiple Escherichia coli strains growing in an assortment of culture conditions varying in terms of temperature, nutrition level and osmotic pressure. Intriguingly, Fourier transform analyses of the transcriptome identified a common chromosomal periodicity of transcriptomes, which was independent of the variation in genomes and environments. In addition, fitting of the data to a theoretical model, we found that the amplitudes of the periodic transcriptomes were significantly correlated with the growth rates. These results indicated that the amplitude of periodic transcriptomes is a parameter representing the global pattern of gene expression in correlation with the bacterial growth rate. Thus, our study provides a novel parameter for evaluating the adaptiveness of a growing bacterial population and quantitatively predicting the growth dynamics according to the global expression pattern.

scholarly journals In Situ Growth Rates and Biofilm Development of Pseudomonas aeruginosa Populations in Chronic Lung Infections

2007 ◽  
Vol 190 (8) ◽  
pp. 2767-2776 ◽  
Author(s):  
Lei Yang ◽  
Janus A. J. Haagensen ◽  
Lars Jelsbak ◽  
Helle Krogh Johansen ◽  
Claus Sternberg ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Growth Rates ◽  
Growth Dynamics ◽  
Chronic Infections ◽  
Lung Infections ◽  
New Perspective ◽  
Biofilm Development

ABSTRACT The growth dynamics of bacterial pathogens within infected hosts are a fundamental but poorly understood feature of most infections. We have focused on the in situ distribution and growth characteristics of two prevailing and transmissible Pseudomonas aeruginosa clones that have caused chronic lung infections in cystic fibrosis (CF) patients for more than 20 years. We used fluorescence in situ hybridization (FISH) directly on sputum specimens to examine the spatial distribution of the infecting P. aeruginosa cells. Mucoid variants were present in sputum as cell clusters surrounded by an extracellular matrix, whereas nonmucoid variants were present mainly as dispersed cells. To obtain estimates of the growth rates of P. aeruginosa in CF lungs, we used quantitative FISH to indirectly measure growth rates of bacteria in sputum samples (reflecting the in vivo lung conditions). The concentration of rRNA in bacteria isolated from sputa was measured and correlated with the rRNA contents of the same bacteria growing in vitro at defined rates. The results showed that most cells were actively growing with doubling times of between 100 and 200 min, with some growing even faster. Only a small stationary-phase subpopulation seemed to be present in sputa. This was found for both mucoid and nonmucoid variants despite their different organizations in sputum. The results suggest that the bacterial population may be confronted with selection forces that favor optimized growth activities. This scenario constitutes a new perspective on the adaptation and evolution of P. aeruginosa during chronic infections in CF patients in particular and on long-term infections in general.

Development and assessment of a high-throughput biofilm and biomass testing platform

2021 ◽  
Vol 30 (Sup7) ◽  
pp. S36-S46
Author(s):  
Hosan Kim ◽  
Matthew Aquino ◽  
Mina Izadjoo
Keyword(s):  
Growth Rate ◽  
High Throughput ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
High Throughput Screening ◽  
Bacterial Strains ◽  
Bacterial Growth Rate ◽  
Testing Platform ◽  
Biofilm Development

Objective: To develop and evaluate a simple platform technology for developing static biofilms in a 96-well microtitre plate for various downstream applications. The technology allows monitoring of growth rate, biofilm formation and quantifying biofilm biomass by using crystal violet (CV) and safranin O (SO) staining over seven-day time periods for pathogens including clinical isolates most commonly associated with hard-to-treat wound infections. Method: A total of 157 bacteria including Acinetobacter, Enterobacter, Klebsiella, Pseudomonas and Staphylococcus spp. were used in the study. Bacterial growth was measured at 600nm optical density (OD). Biofilm formation was monitored and assessed quantitatively with CV at 570nm and SO staining at 492nm for one-, two-, three- and seven-day incubation periods. Results: Bacterial growth rate and static biofilm biomass in the 96-well plates varied for various strains tested. Both CV and SO staining showed similar results in the biomass, with SO assay displaying more reproducible data throughout the study. Most of the strains were metabolically active even at the seven-day incubation period. Microbial adherences of all bacterial strains on the plastic surface was assessed with CV staining: 28 Acinetobacter, 17 Staphylococcus, 12 Pseudomonas and four Enterobacter strains were strong biofilm producers. Moderate biofilm-producing strains included 27 Staphylococcus, 14 Acinetobacter, eight Pseudomonas and three Enterobacter. Weak biofilm-producing strains included: 33 Staphylococcus, six Enterobacter, two Pseudomonas and one Acinetobacter. Only one Pseudomonas aeruginosa strain did not develop biofilm. Conclusion: Our results demonstrate the feasibility of using 96-well microtitre plates as a high-throughput platform for quantitative measurement and assessment of biofilm development over time. Studying microbial adherence or biofilm biomass generated on various surfaces using a high-throughput system could provide valuable information for in vitro testing and developing therapeutics for biofilm infections. Employing the biofilm testing platform described in this study makes it possible to simultaneously develop different biofilms formed by specific pathogens, and study potential association between the quantity of bacterial biomass and strength of a biofilm formed by specific wound pathogens. In addition, the described testing approach could provide an optimal model for standardised and high-throughput screening of candidate antibiofilm therapeutics.

scholarly journals The common chromosomal periodicity of transcriptomes is correlated with the bacterial growth rate

2020 ◽  
Author(s):  
Motoki Nagai ◽  
Masaomi Kurokawa ◽  
Bei-Wen Ying
Keyword(s):  
Gene Expression ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Bacterial Population ◽  
Gene Expression Pattern ◽  
Growth Dynamics ◽  
Bacterial Growth Rate ◽  
Global Pattern ◽  
Global Parameter ◽  
Whole Transcriptome

AbstractThe growth rate, representing the fitness of a bacterial population, is determined by the whole transcriptome. Chromosomal periodicity is a representative overall feature of the whole transcriptome; however, whether and how it is associated with the bacterial growth rate are unknown. To address these questions, we analyzed a total of 213 transcriptomes of genetically differentiated Escherichia coli strains growing in an assortment of culture conditions varying in terms of temperature, nutrition level and osmotic pressure. Intriguingly, the Fourier transform identified a common chromosomal periodicity of transcriptomes, which was independent of the variation in genomes and environments. In addition, fitting of the theoretical model found that the amplitudes of the periodic transcriptomes were significantly correlated with the growth rates. This novel finding successfully identified a single parameter representing the global pattern of the whole transcriptome for the first time and indicated that bacterial growth was correlated with the magnitude of chromosomal differentiation in gene expression. These results provided an alternative global parameter for evaluating the adaptiveness of a growing bacterial population and provided a quantitative rule that makes it possible to predict the growth dynamics according to the gene expression pattern.

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